Procter & Gamble, one of the world's highest-spending advertisers, has called on the media buying and selling industry to become transparent in the face of "crappy advertising accompanied by even crappier viewing experiences."

P&G has given agencies a year to get to "a transparent, clean and productive media supply chain," or risk losing its business, according to Chief Marketing Officer Marc Pritchard, speaking at the IAB Annual Leadership Meeting, a digital advertising industry conference in Hollywood, Florida, on Sunday.

He called for marketers to follow its lead in using one advertising "viewability" standard. P&G – which spent $2.8 billion on marketing and promotion in the year to end June 2016, according to its annual report - will use a Media Ratings Council set standard to understand whether online advertising reaches human viewers, rather than bots, for example.

P&G's Marc Pritchard at the IAB's Annual Leadership Meeting 2017

"Better advertising and media transparency are closely related. Why? Because better advertising requires time and money, yet we're all wasting way too much time and money on a media supply chain with poor standards adoption, too many players grading their own homework, too many hidden touches, and too many holes to allow criminals to rip us off," Pritchard said, according to a transcript of the speech seen by CNBC.com.

"We have a media supply chain that is murky at best and fraudulent at worst. We need to clean it up, and invest the time and money we save into better advertising to drive growth," he added.

His comments come as a survey from the World Federation of Advertisers revealed that large brands are reviewing contracts related to almost $3 billion of spend on programmatic advertising. The technology automates digital ad placement, but whether ads are seen by people has been questioned. "We serve ads to consumers through a non-transparent media supply chain with spotty compliance to common standards, unreliable measurement, hidden rebates and new inventions like bot and methbot fraud," Pritchard said.

P&G has been partly to blame, Pritchard said, in accepting multiple viewability metrics, for example. Pritchard added that the business had not scrutinized agency contracts closely enough, allowing one to use P&G's money as a "float".

P&G called for the marketing and media industry to adopt one viewability standard for online advertising, use third-party measurement verification, get transparent agency contracts and prevent ad fraud by working with industry body the Trustworthy Accountability Group. Its fifth call to action is to "vote with our dollars," or stop working with agencies, suppliers and ad tech companies that don't comply with its requirements.